Biological cell membranes protect cells from toxins and encourage nutrients to enter. They also repair themselves. Manufactured membranes with similar functions are needed in such areas as water purification and drug delivery, but finding synthetic proteins to create such membranes has proven challenging.

Researchers at Pacific Northwest National Laboratory have developed well-ordered, synthetic, protein-like polymers, or peptoids, that mimic natural proteins. These peptoids are inexpensive to produce, versatile, and customizable for specific forms and functions. The key to their creation is controllable self-assembly at the molecular level.

PNNL’s approach combines advanced chemistry and microscopy to create peptoids that form a pattern of nanoribbons which self-assemble into a membrane sheet. These sheets are thinner but more stable than a soap bubble. They can withstand being submerged in a variety of liquids and can even repair themselves after damage. Once coated on solid surfaces, the sheets create a highly programmable coating material that could be used for hard tissue regeneration and repair. The approach provides a new and robust platform from which to assemble synthetic polymers into biomimetic materials.

Recent studies demonstrated the ability of these peptoid nanomembranes to be used for therapeutic gene delivery, overcoming issues of efficiency and potential toxicity. Researchers wove the nanomembranes into a flower-like particle about one thousand times smaller than the width of a piece of paper. When inserted near a cell, the particles were able to make their way smoothly through the cell to release their medicine at the spot it was most needed.

APPLICABILITY

Peptoid nanomembranes can be used for a variety of purposes, such as the following:

• Surface coatings to repair or regenerate bones
• Cell adhesion
• Antifouling coatings
• Antibacterial materials
• Water filters
• Sensors
• Drug delivery mechanisms
• Fuel cells and other energy applications.